Power actuated mechanism for elevator closures



June 16, 1959 5, w. R, JR 2,890,881

POWER ACTUATED MECHANISM FOR ELEVATOR CLOSURES Filed June '7, 1955 I 1 fl FIG. l

J I I I I I I I I I! I I 2i 2! Fl 3 B'fM/l/Y/N awry/40 rum 2 m.

INVENTOR BY ATTOQNEY 2,890,881 POWER ACTUATED MECHANISM FOR ELEVATOR CLOSURES Benjamin Whitehead Tucker, Jr., South Orange, N.J., as-

signor to Otis Elevator Company, New York, N.Y., a corporation of New Jersey Application June 7 1955, Serial No. 513,698 3 Claims. (Cl. 268 -43) This invention relates to apparatus for operating closures by power, especially power actuated mechanism for closures of elevator installations.

There are various arrangements for operating closures for the entranceways of elevator systems. In many constructions the closure operator is powered by an electric motor which acts through reduction gearing to effect movement of the closure. This mechanism on doors is often connected to one or more hydraulic dashpots by a series of cranks and levers to cushion the terminal movement of the closure. Such arrangements result in a complicated structure which is noisy in operation, difiicult to adjust, troublesome to maintain and expensive to manufacture.

It is, therefore, an object of this invention to provide for elevator closures a power actuated mechanism in which the power transmission linkage and the shock absorbing or cushioning devices are integrally associated within a unitary housing in such manner that a single reservoir of lubricating fluid serves both as the gear lubricant and as the hydraulic cushioning fluid.

This invention utilizes a torque type operating device wherein the closure arm plate is integrally united with a low speed shaft and hydraulic cushioning means is utiiized to counteract the torque on a geared motor, thus acting through the low speed shaft to retard the closure as it approaches either one of its extreme positions. This arrangement obviates the above mentioned problems by eliminating the multiple cranks and levers and substitutes therefor a simple, economical, noiseless unitary construction. i h

In carrying oiit'the invention according to the arrangement described a reversible electric motor operates the reduction gearing which drives a low speed shaft having a closure arm plate attached thereto and which also drives a reciprocal rack. The rack hasa piston on each end sliclab'le in oppositely disposed cylinders. Through the gearing the motor controls the acceleration of the elevator closure and thedeceleration of said closure is regulated by the hydraulic cushioning device and its adjusting valves. Thus with one end of the double acting piston applying pressure on the v cylinder fluid when the closure is being opened and the other end of said piston operating when the closureis being closed, the gear mechanism is provided for reciprocating motion with internal cushioning at the extremities of travel. The length of the cushioning zone m ay be adjustedfby anadjusting valve which permits the passage of fluid from the cylinder through an escape chamber; the intensity of the cushioning may he adjusted by a screw valve which regulates the passage of fluid from the cylinder through a bypass duct. The cylinder escape chamber and by-pass ,duct lead to a fluid reservoir in the lower portion of the housing and the reservoiris at sucha level to lubricate the reduction gearing ,as well as to serve as the hydraulic fluid for the cushioning device.

The invention will be described as applied to an elevator .door and the power operating mechanism is arranged to operate the door in both directions. It is 2 within the scope of this invention to utilize closure operator with any of the sliding type elevator doors]. Other advantages of this inevntiori will be apparent from the following description of the preferred embodiment.

In the drawings p I p h Fig. 1 shows the preferred embodiment of the operator mounted in position for opening and closing sliding type elevator doors; A h I Fig. 2 is a sideview showing the closure arni plateintegrally connected to a low speed shaft andportions of the housing broken away to show the relative posi tions of the reduction gear mechanism; p h

Fig. 3 shows a partial front elevation view of the operator with portions broken away to show the reduction gear mechanism and sectional views of the double-acting piston and cylinder; n t t Fig. 4 is a sectional view taken on line 4-..4 in Fig. 2 and shows a valve which adjustably positions the point at which the cushioning commences; and p i h ,Fig. 5 is a sectional view taken. on line 5-5 in Fig, 2 and shows a valve which controls the intensity of the cushion. y p p p In the drawing there isdisclosed in Fig. l a sliding elevator door 1 to which the invention nay be applied. The elevator door 1 is supported by hangers running on a r ck m un e on. he ea fr mework 2; Th r ver ible operating motor 3 and a gear housing 4 also are moun ed n th c f amework, One end f the mtating haf 5 of the mo or ex end in o he gear housin 4 as sh wn in Fig- 2 nd base he i al p ion 6 se ured to .said end. The helical P n on dri es a ar gear .7 mounted on a shaft 11, meshing with helical gear teeth 8 on the ut p r phery of th gear 7 and. as sh wn in s- 3- The ends at shaft 11 aremount din bea i g whi h re s pport d y the ge r h using in a convenion l manner. .SPIII gear tee h 10 are tcrzm d on shaf 11 an mes ith spu se r ee h 1. on a se o d p nion o g 1 h h drives the lo pee sha t .1 The eth .10 are longated nd e ten into the Mount ng p ture for g r scrvins as spline or dri ing ha 11 by me ns o ge r Fig.- 2 the pinion 1. i illu trated as beinso f ebfmm e 7 al ng th otating ax of s ah '1 and t e .fl n 1 s cur d o t e low spe sh f 14 by means of long. d mlk y 1.5-. he closur p t ng member is locatedout id t e ima ing 4 n on end of t e low speed h .14 ex ends o tside th ho ng 4 for connection ther w th l tes e lyrfi rm d on e expo ed Bird o shaf 1 is edger m. pl e to whi h the door a 17 i a ta h d a by. achi scrcW Th low. peed sha .14 is ar a ed for ci lay motion throug n a c of pp ox m ely 1 29. as the door rm m e rom one en of t sweep at the door closed position to the alternate end of its sweep at the door opened position.

A pair o r t ding evice a e loc e w n th ower P rtion of he gear housi g nd a nte loc d w th th gear reduction train t c shi n he nal cl s ng. an p ing f the cl vetorj o r- Diametr ally ppo t to h Point of nt ct-of h pinion 1, nd the in rmed a shaft 11, the gear teeth 12. of pinion 13 mesh with the teeth 19 of a reciprocating rack 18}. The outer ends of 'the rack 18 are each provided with a piston 201t o slide in a pair of oppositely disposed cylinders 21. motor 3 thus :actuates the gear reduction mechanism which in turn drives the shaft 14 in an oscillatory manner and which also drives the rack 18 in a reciprocating manner,

permitting the piston on one .side .of the rack to. cushion the door opeinng operation and the piston on theiopposite side of the rack .torcushion the door closing .operation. Inasmuch as the structure and operation of the two pistons in their respective cylinders at opposite sides of theraek are identical, the illustration in Fig. 3 and the 3 I accompanying description arerestricted to that for only one side.

In order to prohibit retardation on the suction stroke of the piston, a passage 22 is provided in the piston head having a one-way check valve 26 positioned therein. Thus the hydraulic fluid is permitted to pass through the piston during the suction stroke but is prevented from passage therethrough during the compression stroke.

I The cylinder 21 is positioned within the lower portion of the gear housing 4 and is integrally formed therewith. As shown in Fig. 4 an escape chamber 27 permits the passage of the hydraulic fluid between the cylinder 21 and the, reservoir 28 in the lower portion of the gear housing.

A series of ports 29 are longitudinally spaced along the cylinder wall connecting the escape chamber to the cylinder and upon pressure by the piston the fluid will be forced from the cylinder 21 through a selected port 29 into the escape chamber 27. Positioned in the escape chamber 27 is an adjusting valve 30 having a series of apertures 31 longitudinally and radially spaced along the hollow end portion 32. -The radial apertures 31 in the valve are brought into alignment with the ports 29 by rotation of the valve stem 33. As the piston moves toward the head end of the cylinder, the fluid escapes freely through whichever valve aperture 31 is lined up with the cylinder port 29. This allows the piston to move without restraint or cushioning until the piston head seals off this port and adjustment as to the length of the cushioning zone is made possible by rotation of the valve stem 33 to align a selected port 29 with its corresponding valve aperture 31. The adjusting valve 30 is made accessible by having its stem 33 protrude through the cylinder end plate 34 and through 'apacking gland and packing nut 35. The end plate 34 is secured to the gear housing by hexagon head cap screws 36 or any other suitable fasteners.

As illustrated in Fig. 5, the intensity of the cushioning is controlled by means of a regulating screw valve 37 having a stem 38 and a long, smooth cylindrical end 39, and is secured to the end plate 34 in a vertical position by a packing nut 40. The smooth end 39 of the screw valve fits into a by-pass duct 41 in the end plate, which duct permits the passage of fluid between the cylinl der 21 and a second escape chamber 42. Internal threads 43 in the by-pass duct cause the fluid, forced out of the cylinder, to flo'w in a long helical path through the threads 43 around smooth end 39 of the screw valve. Prior regulating screw valves have restricted the escapement of fluid by reducing the cross-sectional area of the orifice which resulted in a very small opening requiring high velocity that generated noise. Furthermore, the small opening was readily plugged by any dirt or foreign matter in the fluid. Here the escapement area, namely, the crosssection within the threads 43, remains constant and the intensity is varied by increase or decrease of the length of the long helical path through the threads around the smooth end 39 of the screw valve 37.

After the piston has moved forward into the cylinder and passes the selected cylinder port 29, the confined fluid is forced through the by-pass duct 41, into the second escape chamber 42 and then back into the reservoir 28. The fluid in the reservoir is then utilized as a lubricant for the gear reduction mechanism and the reciprocating rack, which results in a noiseless operation with smooth performance.

While only one side of the gear housing has been described in connection with the adjusting valve and screw valve, it can be seen from Fig. 1 that the opposite end plate also uses identical valves. Thus the cushioning may Adjustment of each of the four valves is facilitated by mounting the valve stems on the outside ofthe cylinder end plate where they are accessible and 4 Y if replacement is necessary the complete end plate may be removed.

While only the preferred embodiment of the invention has been described by way of illustration, various modifications may be made Within the spirit of the invention, and therefore it is intended that the appended claims cover all such modifications as fall within the spirit and scope of this invention.

What is claimed is:

1. Elevator closure operating mechanism comprising, a housing having an upper portion and a lower portion, lubricating fluid in said lower portion, a speed reduction device in said upper portion and extending into said fluid to carry said fluid to said upper portion to lubricate the portion of said speed reduction device in said upper portion, a reversible motor integral with said housing and connected to said reduction device to transmit motion thereto, a closure operating member outside said housing, said reduction device being connected to said member for eifecting operation thereof, retarding mechanism, including a pair of oppositely disposed cylinders integral with said lower portion, a double acting piston for said cylinders, a rack connected to said double acting piston and actuated by said reduction device, to drive said double acting piston, each of said cylinders having an escape chamber and a by-pass duct, an adjustable valve in each of said escape chambers to control the flow of fluid through said chambers to preset a retarding zone for said closure operating mechanism and a regulating valve in each of said by-pass ducts to control the rate of flow of fluid through said ducts to regulate the retarding intensity of said closure operating mechanism.

2. Power actuated mechanism for an elevator closure comprising, a gear housing having an upper and lower portion, a reversible electric motor mounted on said housing having a shaft extending into said upper portion, reduction gearing connected to said shaft end extending into said lower portion of said housing, a low speed shaft having its inner end extending into said housing and operated by said reduction gearing, a closure operating member on the outer end of said low speed shaft to open and close said closure, a rack located in said lower portion and operated by said reduction gearing, a double acting piston connected to said rack for reciprocating motion therewith, a pair of oppositely disposed cylinders formed in said lower portion of said housing, one of said cylinders receiving one end of said double acting piston and the other of said cylinders receiving the other end of said double acting piston each of said pistons having a chamber connecting its respective cylinder with said lower portion, and lubricating fluid in said lower portion, said reduction gearing extending into said lower portion to carry said fluid to said upper portion for lubrication of said gears therein, a valve in each of said chambers actuated by the motion of said piston in said fluid to trap said fluid in said cylinder to cushion the closing and opening stroke of said closure.

3. A power actuated mechanism for an elevator closure comprising, a gear housing having an upper and lower portion, a gear reduction mechanism located within said housing, a reversible motor mounted on the outside of said housing and having a shaft connected to said gear reduction mechanism, a closure operating member outside said housing and connected to said gear reduction mechanism to be driven at a relatively slow speed, a pair -of oppositely disposed pistons in the lower portion of said housing, a reciprocating rack driven by positive engagement with said mechanism, said rack being connected to both said pistons to actuate said pistons during the closures opening and closing cycle, said lower portion having a pair of oppositely disposed cylinders formed therein, one of said pistons being encased in each of said cylinders, lubricating fluid in the lower portion of said housing and in said cylinders, said gear reduction mechanism extending into said lower portion to carry fluid to said upper portion to lubricate the gears therein, each of said pistons having an escape chamber for each cylinder leading to said lower portion, and a valve in each of said escape chambers actuatable by movement of said pistons to control the flow of lubricating fluid through said chambers to retard movement of said closure.

4. A power actuated mechanism for opening and closing an elevator door slidably supported by the elevator car framework comprising, a housing attached to the framework, a reversible motor mounted on the outside of said housing and having its shaft extending into said housing, a second shaft having its inner end extending into the housing, a gear reduction train located within said housing and connecting said shafts to transmit motion from the motor shaft to said second shaft, a door arm plate attached to the outer end of said second shaft, door arm linkage joined to said plate to actuate said door, a gear toothed rack in said housing being driven by said train, a pair of oppositely disposed cylinders formed integrally with the housing, a double acting piston integral with said rack and adapted to reciprocate in said cylinders, lubricating fluid within said housing and said cylinders, said housing serving as a fluid reservoir, said gear reduction train extending into said reservoir, each of said cylinders having an escape chamber formed between the interior of that cylinder and said fluid reservoir by means at least two ports alined axially in that cylinder Wall, adjustable valve means disposed in each of said escape chambers to select one of said ports for fluid flow to preset when in the opening and closing movement of said door retarding force is applied to the piston movement to cushion said door, each cylinder having a by-pass duct connecting the end of each cylinder to said reservoir, and regulating valve means disposed in each of said ducts, said valve means being adjustable to vary the distance which the fluid must travel through said bypass ducts to control the rate of flow of said fluid through said duct to regulate the intensity of the cushion for the door.

5. A power actuated mechanism for an elevator door slidably supported by the car framework comprising, a housing having an upper and lower portion supported on said framework, a reversible motor mounted on said housing and having its shaft extending into upper portion of said housing, a helical pinion in said housing mounted on the inner end of said motor shaft, a second shaft in upper portionof said housing, said second shaft having spur gear teeth formed thereon, a gear having helical gear teeth mounted on said second shaft to be driven by said helical pinion, a second gear in said housing, said second gear having spur gear teeth driven by said spur gear teeth on said second shaft, said second gear and said gear having helical gear teeth extending into the lower portion of said housing, a low speed shaft upon which the second gear is mounted, said low speed shaft extending outside the housing, a door arm plate on the outer end of said low speed shaft for oscillating movement therewith, operating means connecting said plate to said door to open and close said door, a double acting piston integral with a rack which meshes with the spur gear teeth on said second gear for reciprocating motion, a pair of oppositely disposed cylinders integral with the lower portion of said housing for receiving the double acting piston, lubricating fluid in a reservoir formed by said cylinders and the lower portion of said housing, said gears extending into said fluid to carry fluid into said upper portion of said housing to lubricate said gears therein, said cylinders each having a passage opening into the lower portion of said housing, and valve means in each passage to regulate the flow of fluid through said passage to cushion said door as it reaches its open and closed positions.

6. Power actuated mechanism for opening and closing an elevator door comprising; a housing having an upper portion and a lower portion; a reversible motor mounted on the outside of said housing; a gear reduction train within said housing driven by said motor; an operating member for said door driven by said gear reduction train; lubricating fluid within a reservoir provided by said lower portion of said housing into which fluid said gear reduction train extends to carry said lubricating fluid into said upper portion to lubricate the portion of said gear reduction train in said upper portion, retarding mechanism for cushioning the opening and closing movements of said door, said retarding mechanism comprising, a pair of oppositely disposed cylinders integral with said lower portion of said housing, a double acting piston for said cylinders, a rack connecting said pistons and driven by said gear reduction train, each of said cylinders having an escape chamber for said fluid, and adjustable valve means disposed in each of said chambers to control the rate of fluid flow into its respective chamber from the cylinder for which it is provided to adjust the intensity of said cushioning.

7. Power actuated mechanism for opening and closing an elevator door comprising; a housing having an upper portion and a lower portion; a reversible motor having its frame secured to said upper portion of said housing on the outside thereof and having its shaft extending into said housing; a gear reduction train within said housing including a pinion on the end of said shaft, a large gear driven by said pinion, a second pinion driven by said large gear and a second gear driven by said second pinion; a second shaft driven by said second gear and extending outside said housing; an operating member for said door secured to the outer end of said second shaft; a pair of oppositely disposed cylinders integral with said lower portion of said housing; a double acting piston for said cylinders; a rack integral with said pistons and driven by said second gear; lubricating fluid within a reservoir provided by said lower portion of said housing and within said cylinders, said lubricating fluid covering said rack and said large gear extending into said reservoir and carrying lubricating fluid therefrom to said pinions to lubricate said gear reduction train; a check valve for each piston to 'admit fluid from. said reservoir to its cylinder on its suction stroke; an escape chamber for said fluid from each of said cylinders to said reservoir, each chamber having an adjusting valve disposed therein for determining the point of cut-oif of fluid flow into that chamber from the cylinder for which it is provided; a. bypass duct for each cylinder connecting the end of that cylinder to said reservoir whereby said lubricating fluid also serves as hydraulic means to cushion movement of said door as it reaches open and closed positions; and a regulating valve disposed in each of said. ducts to regulate the intensity of said cushion provided by the cylinder for which that duct is provided 8. Power actuated mechanism for opening and closing an elevator door comprising; a housing; a gear reduction train within said housing; a reversible motor for driving said gear reduction train; an operating member for said door driven by said gear reduction train; and retarding mechanism for cushioning the final opening and closing movements of said door, said retarding mechanism including a pair of oppositely disposed cylinders integral with said housing, a double acting piston for said cylinders, means driven by said gear reduction train for actuating said pistons, fluid within said. cylinders, an escape chamber for said fluid from each of said cylinders, each chamber having an adjusting valve disposed therein for determining the point of cut-off of fluid flow into that chamber from the cylinder for which it is provided for adjusting the length of the cushion.

References Cited in the file of this patent UNITED STATES PATENTS 1,544,901 Griflin July 7, 1925 1,760,063 Hynes May 27, 1930 2,003,534 Green June 4, 1935 2,276,338 Potter et al. Mar. 17, 1942 

